1. Field
This application relates generally to devices, systems and methods for the treatment of the spine, and more specifically, to access into an intervertebral space, spinal implants, pedicle screws, fixation systems and related tools, systems and methods.
2. Description of the Related Art
Surgical approaches to the intervertebral space are utilized for a variety of indications and purposes, such as, for example, biopsy (e.g., for evaluation of possible infection, other pathology, etc.), discectomy (e.g., for decompression of nerve roots, to prepare for subsequent fusion procedures, etc.), disc height restoration or deformity correction, disc replacement or repair (e.g., annular repair), discogram, gene therapy and/or other procedures or treatments.
Various approaches are currently used to access the interbody or intervertebral space of a patient's thoracic, lumbar and sacral spine. These include anterior approaches (ALIF) (e.g., open, mini-open retroperitoneal, etc.), lateral approaches (e.g., costotranversectomy, extreme lateral, etc.), posterolateral approaches (e.g., posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), etc.) and axial approaches (e.g., axial lumbar interbody fusion). Further, many minimally invasive and percutaneous approaches rely on radiographic landmarks with or without direct view to access a targeted interbody space. In addition, many, if not all, of these currently used approaches require violation of the disc annulus to access the disc space.
Fusion surgery of the thoracic, lumbar and sacral spine is often performed for a variety of indications, including degenerative joint disease, deformity, instability and/or the like. Typically, traditional fusion approaches involve relatively large, open incisions performed under direct vision. Minimally invasive surgical techniques and corresponding surgical implants have become more popular in an attempt to reduce morbidity and generally improve outcomes. Multiple variations of percutaneous systems (e.g., pedicle screw and rod systems, facet screw systems, etc.) have been developed. Such systems can allow for instrumentation placement with fluoroscopic guidance (e.g., using radiographically recognizable body landmarks) and/or other imaging technologies. Current fusion techniques, including those that utilize open and minimally invasive approaches, often require direct visualization. However, such techniques typically involve traversing spaces that are occupied by neural elements. Thus, these neural elements need to be retracted or otherwise moved during the execution of spinal procedures that precede implantation (e.g., annulotomy, discectomy, disc space and/or vertebral endplate preparation, etc.). Retraction of sensitive neural elements can also be required during the delivery of an implant to the spine.
These approaches typically require contact and retraction of nerve roots and/or sensitive visceral organs, blood vessels and/or other sensitive portions of the anatomy. Contact and retraction of these structures can place them at risk, thereby increasing the likelihood of complications and damage to a patient. Accordingly, a need exists for improved approaches for spinal fusion and/or access to intervertebral spaces.